Curated OER
Are you in Golden Shape
Students solve and verify the solution for unknown measures. In this geometry lesson, students identify the properties of circles. They use the arc, angle and segment relationship to find the missing measures.
Curated OER
Trapezoids
In this trapezoids worksheet, 10th graders solve 5 different problems related to trapezoids and applying the appropriate theorem. First, they define a trapezoid, including its bases, legs, and base angles. Then, students use the...
Curated OER
Triangle Inequality Theorems Investigation
Students estimate and measure triangles. In this geometry lesson, students identify the relationship between three sides and a triangle. They use the inequality theorem to decide if a triangle will be formed or not.
Curated OER
Exploring Special Segments in Triangles
Students discover that four special segments have a common intersection point. They identify the position of the intersection point in triangles. They produce conjectures about areas of the divided triangles.
Curated OER
Got Complements? with Cabri Jr.
Learners use the axes and measure angle tool to explore and calculate complementary angles with Cabri Jr. They also identify what happens to the calculation as they drag the endpoint into a different quadrant. Finally, they label each...
Curated OER
Triangle Puzzler
Students are introduced to some basic concepts of geometry. They explain that the definition of a triangle is a figure with three sides, three angles, and three points. Triangles can be named by using three points in their correct sequence.
Illustrative Mathematics
Midpoints of the Sides of a Paralellogram
This task asks learners to prove that the segment joining the midpoints of two sides of a parallelogram is both congruent and parallel to an adjacent side of the parallelogram. The activity would be good to use in a discussion about how...
Curated OER
Perimeter All Around
Students explore perimeter and area of regular and irregular polygons. They experiment with color squares and create different arrangements using the same number squares. Then they compare the area and perimeter measurements of each.
Curated OER
Parts of Similar Triangles
In this parts of similar triangles activity, 10th graders solve and complete 15 different statements related to naming the parts found in similar triangles. First, they identify each definition stated that describes an everyday usage of...
Curated OER
Geometry, Measurement & Reasoning
Students complete worksheets involving rotational symmetry. For this geometry lesson, students complete worksheets to identify rotational symmetry and rotations. They compare and contrast rotated figures. Students examine the...
Curated OER
Tangent Properties
Students explore properties of tangent lines. In this properties of tangent lines lesson, students discuss the perpendicular relationship between a tangent line on a circle and the circle's radius. Students use that relationship to...
Curated OER
Parallelograms
In this parallelograms worksheet, 10th graders identify and describe a quadrilateral, a diagonal, and a parallelogram in 7 different problems. First, they find the values of x, y, and z in each quadrilateral to prove that it is a...
Curated OER
Identify Similar Figures
Students explore the concept of similar figures. In this similar figures lesson, students develop the idea that similar figures are a different size but the same shape by comparing similar rectangles. Students use patty paper to trace...
Curated OER
Betweenness and the Sum of Parts
High schoolers differentiate lines and angles using betweenness in this geometry lesson. They differentiate angles and lines using Cabri Jr. and analyze the data and make conjecture.
Curated OER
Seeing Solar Storms in STEREO-II
In this solar storms worksheet, students use a diagram given the location of two STEREO spacecraft satellites, a coronal mass ejection, the sun and the Earth to solve 2 problems about the coronal mass ejection. Students use segments,...
Key Curriculum Press
Triangle Inequalities
Properties about triangles are explored in this instructional activity. Geometers make conjectures about the length of a triangle's sides, the length of the angles in relation to the length of the sides, and the measure of the exterior...
Curated OER
Building Blocks of Geometry
In this geometry activity, students answer questions about midpoints, distance, lines and segments. They are given different shapes and asked to calculate the angles, and sides of polygons.
EngageNY
Informal Proofs of Properties of Dilations
Challenge the class to prove that the dilation properties always hold. The instructional activity develops an informal proof of the properties of dilations through a discussion. Two of the proofs are verified with each class member...
Willow Tree
Common Geometric Figures
Geometry could be called the study of figures. An overview of the figures found in a typical geometry course contains a study of different triangles, quadrilaterals, and regular polygons.
Charleston School District
Review Unit 2: Congruence and Similarity
Review for the test with a comprehensive list of terms and concepts for the unit on congruence and similarity. It divides divides the sections in the order of the lessons presented during the unit.
EngageNY
Reflections
Facilitate creativity in your math class as individuals learn the definition of a geometric reflection and correctly construct a model, as well as its reflected image. They use a perpendicular bisector and circles to elaborate on...
Curated OER
Up For Change?
Students explore similar objects. They participate in a series of hands-on, multimedia and online activities to examine how the edge length affects the angle measures, perimeters and areas of similar regular polygons. Students find the...
Curated OER
Perimeter
In this perimeter instructional activity, 10th graders solve and complete nineteen various geometry problems. First, they find the length of given segments in addition to the perimeter of a kite. Then, students find the value of a...
Curated OER
The Triangle Midsegment Theorem
In this geometry worksheet, 10th graders identify the vocabulary associated with the Triangle Midsegment Theorem and solve problems in which they find the size of a missing angle or segment. The one page worksheet contains nineteen...